[MTD] NAND cleanup nand_scan

Seperate functionality out of nand_scan so the code is more
readable. No functional change. First step of simplifying
the nand driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 233 insertions, 174 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index afa77d1ed900..37db98a58c34 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -76,6 +76,7 @@
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -2333,42 +2334,50 @@ static void nand_free_kmem(struct nand_chip *this)
                 kfree(this->controller);
 }
 
-/* module_text_address() isn't exported, and it's mostly a pointless
-   test if this is a module _anyway_ -- they'd have to try _really_ hard
-   to call us from in-kernel code if the core NAND support is modular. */
-#ifdef MODULE
-#define caller_is_module() (1)
-#else
-#define caller_is_module() module_text_address((unsigned long)__builtin_return_address(0))
-#endif
-
-/**
- * nand_scan - [NAND Interface] Scan for the NAND device
- * @mtd:        MTD device structure
- * @maxchips:   Number of chips to scan for
- *
- * This fills out all the uninitialized function pointers
- * with the defaults.
- * The flash ID is read and the mtd/chip structures are
- * filled with the appropriate values. Buffers are allocated if
- * they are not provided by the board driver
- * The mtd->owner field must be set to the module of the caller
- *
+/*
+ * Allocate buffers and data structures
  */
-int nand_scan(struct mtd_info *mtd, int maxchips)
+static int nand_allocate_kmem(struct mtd_info *mtd, struct nand_chip *this)
 {
-        int i, nand_maf_id, nand_dev_id, busw, maf_id;
-        struct nand_chip *this = mtd->priv;
+        size_t len;
 
-        /* Many callers got this wrong, so check for it for a while... */
-        if (!mtd->owner && caller_is_module()) {
-                printk(KERN_CRIT "nand_scan() called with NULL mtd->owner!\n");
-                BUG();
+        if (!this->oob_buf) {
+                len = mtd->oobsize <<
+                        (this->phys_erase_shift - this->page_shift);
+                this->oob_buf = kmalloc(len, GFP_KERNEL);
+                if (!this->oob_buf)
+                        goto outerr;
+                this->options |= NAND_OOBBUF_ALLOC;
         }
 
-        /* Get buswidth to select the correct functions */
-        busw = this->options & NAND_BUSWIDTH_16;
+        if (!this->data_buf) {
+                len = mtd->oobblock + mtd->oobsize;
+                this->data_buf = kmalloc(len, GFP_KERNEL);
+                if (!this->data_buf)
+                        goto outerr;
+                this->options |= NAND_DATABUF_ALLOC;
+        }
 
+        if (!this->controller) {
+                this->controller = kzalloc(sizeof(struct nand_hw_control),
+                                           GFP_KERNEL);
+                if (!this->controller)
+                        goto outerr;
+                this->options |= NAND_CONTROLLER_ALLOC;
+        }
+        return 0;
+
+ outerr:
+        printk(KERN_ERR "nand_scan(): Cannot allocate buffers\n");
+        nand_free_kmem(this);
+        return -ENOMEM;
+}
+
+/*
+ * Set default functions
+ */
+static void nand_set_defaults(struct nand_chip *this, int busw)
+{
         /* check for proper chip_delay setup, set 20us if not */
         if (!this->chip_delay)
                 this->chip_delay = 20;
@@ -2403,6 +2412,17 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                 this->verify_buf = busw ? nand_verify_buf16 : nand_verify_buf;
         if (!this->scan_bbt)
                 this->scan_bbt = nand_default_bbt;
+}
+
+/*
+ * Get the flash and manufacturer id and lookup if the typ is supported
+ */
+static struct nand_flash_dev *nand_get_flash_type(struct mtd_info *mtd,
+                                                  struct nand_chip *this,
+                                                  int busw, int *maf_id)
+{
+        struct nand_flash_dev *type = NULL;
+        int i, dev_id, maf_idx;
 
         /* Select the device */
         this->select_chip(mtd, 0);
@@ -2411,158 +2431,194 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
         this->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 
         /* Read manufacturer and device IDs */
-        nand_maf_id = this->read_byte(mtd);
-        nand_dev_id = this->read_byte(mtd);
+        *maf_id = this->read_byte(mtd);
+        dev_id = this->read_byte(mtd);
 
-        /* Print and store flash device information */
+        /* Lookup the flash id */
         for (i = 0; nand_flash_ids[i].name != NULL; i++) {
+                if (dev_id == nand_flash_ids[i].id) {
+                        type =  &nand_flash_ids[i];
+                        break;
+                }
+        }
 
-                if (nand_dev_id != nand_flash_ids[i].id)
-                        continue;
-
-                if (!mtd->name)
-                        mtd->name = nand_flash_ids[i].name;
-                this->chipsize = nand_flash_ids[i].chipsize << 20;
-
-                /* New devices have all the information in additional id bytes */
-                if (!nand_flash_ids[i].pagesize) {
-                        int extid;
-                        /* The 3rd id byte contains non relevant data ATM */
-                        extid = this->read_byte(mtd);
-                        /* The 4th id byte is the important one */
-                        extid = this->read_byte(mtd);
-                        /* Calc pagesize */
-                        mtd->oobblock = 1024 << (extid & 0x3);
-                        extid >>= 2;
-                        /* Calc oobsize */
-                        mtd->oobsize = (8 << (extid & 0x01)) * (mtd->oobblock >> 9);
-                        extid >>= 2;
-                        /* Calc blocksize. Blocksize is multiples of 64KiB */
-                        mtd->erasesize = (64 * 1024) << (extid & 0x03);
-                        extid >>= 2;
-                        /* Get buswidth information */
-                        busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
+        if (!type)
+                return ERR_PTR(-ENODEV);
+
+        this->chipsize = nand_flash_ids[i].chipsize << 20;
+
+        /* Newer devices have all the information in additional id bytes */
+        if (!nand_flash_ids[i].pagesize) {
+                int extid;
+                /* The 3rd id byte contains non relevant data ATM */
+                extid = this->read_byte(mtd);
+                /* The 4th id byte is the important one */
+                extid = this->read_byte(mtd);
+                /* Calc pagesize */
+                mtd->oobblock = 1024 << (extid & 0x3);
+                extid >>= 2;
+                /* Calc oobsize */
+                mtd->oobsize = (8 << (extid & 0x01)) * (mtd->oobblock >> 9);
+                extid >>= 2;
+                /* Calc blocksize. Blocksize is multiples of 64KiB */
+                mtd->erasesize = (64 * 1024) << (extid & 0x03);
+                extid >>= 2;
+                /* Get buswidth information */
+                busw = (extid & 0x01) ? NAND_BUSWIDTH_16 : 0;
 
-                } else {
-                        /* Old devices have this data hardcoded in the
-                         * device id table */
-                        mtd->erasesize = nand_flash_ids[i].erasesize;
-                        mtd->oobblock = nand_flash_ids[i].pagesize;
-                        mtd->oobsize = mtd->oobblock / 32;
-                        busw = nand_flash_ids[i].options & NAND_BUSWIDTH_16;
-                }
+        } else {
+                /*
+                 * Old devices have this data hardcoded in the device id table
+                 */
+                mtd->erasesize = nand_flash_ids[i].erasesize;
+                mtd->oobblock = nand_flash_ids[i].pagesize;
+                mtd->oobsize = mtd->oobblock / 32;
+                busw = nand_flash_ids[i].options & NAND_BUSWIDTH_16;
+        }
 
-                /* Try to identify manufacturer */
-                for (maf_id = 0; nand_manuf_ids[maf_id].id != 0x0; maf_id++) {
-                        if (nand_manuf_ids[maf_id].id == nand_maf_id)
-                                break;
-                }
+        /* Try to identify manufacturer */
+        for (maf_idx = 0; nand_manuf_ids[maf_idx].id != 0x0; maf_id++) {
+                if (nand_manuf_ids[maf_idx].id == *maf_id)
+                        break;
+        }
 
-                /* Check, if buswidth is correct. Hardware drivers should set
-                 * this correct ! */
-                if (busw != (this->options & NAND_BUSWIDTH_16)) {
-                        printk(KERN_INFO "NAND device: Manufacturer ID:"
-                               " 0x%02x, Chip ID: 0x%02x (%s %s)\n", nand_maf_id, nand_dev_id,
-                               nand_manuf_ids[maf_id].name, mtd->name);
-                        printk(KERN_WARNING
-                               "NAND bus width %d instead %d bit\n",
-                               (this->options & NAND_BUSWIDTH_16) ? 16 : 8, busw ? 16 : 8);
-                        this->select_chip(mtd, -1);
-                        return 1;
-                }
+        /*
+         * Check, if buswidth is correct. Hardware drivers should set
+         * this correct !
+         */
+        if (busw != (this->options & NAND_BUSWIDTH_16)) {
+                printk(KERN_INFO "NAND device: Manufacturer ID:"
+                       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id,
+                       dev_id, nand_manuf_ids[maf_idx].name, mtd->name);
+                printk(KERN_WARNING "NAND bus width %d instead %d bit\n",
+                       (this->options & NAND_BUSWIDTH_16) ? 16 : 8,
+                       busw ? 16 : 8);
+                return ERR_PTR(-EINVAL);
+        }
 
-                /* Calculate the address shift from the page size */
-                this->page_shift = ffs(mtd->oobblock) - 1;
-                this->bbt_erase_shift = this->phys_erase_shift = ffs(mtd->erasesize) - 1;
-                this->chip_shift = ffs(this->chipsize) - 1;
-
-                /* Set the bad block position */
-                this->badblockpos = mtd->oobblock > 512 ? NAND_LARGE_BADBLOCK_POS : NAND_SMALL_BADBLOCK_POS;
-
-                /* Get chip options, preserve non chip based options */
-                this->options &= ~NAND_CHIPOPTIONS_MSK;
-                this->options |= nand_flash_ids[i].options & NAND_CHIPOPTIONS_MSK;
-                /* Set this as a default. Board drivers can override it, if necessary */
-                this->options |= NAND_NO_AUTOINCR;
-                /* Check if this is a not a samsung device. Do not clear the options
-                 * for chips which are not having an extended id.
-                 */
-                if (nand_maf_id != NAND_MFR_SAMSUNG && !nand_flash_ids[i].pagesize)
-                        this->options &= ~NAND_SAMSUNG_LP_OPTIONS;
+        /* Calculate the address shift from the page size */
+        this->page_shift = ffs(mtd->oobblock) - 1;
+        /* Convert chipsize to number of pages per chip -1. */
+        this->pagemask = (this->chipsize >> this->page_shift) - 1;
 
-                /* Check for AND chips with 4 page planes */
-                if (this->options & NAND_4PAGE_ARRAY)
-                        this->erase_cmd = multi_erase_cmd;
-                else
-                        this->erase_cmd = single_erase_cmd;
+        this->bbt_erase_shift = this->phys_erase_shift =
+                ffs(mtd->erasesize) - 1;
+        this->chip_shift = ffs(this->chipsize) - 1;
 
-                /* Do not replace user supplied command function ! */
-                if (mtd->oobblock > 512 && this->cmdfunc == nand_command)
-                        this->cmdfunc = nand_command_lp;
+        /* Set the bad block position */
+        this->badblockpos = mtd->oobblock > 512 ?
+                NAND_LARGE_BADBLOCK_POS : NAND_SMALL_BADBLOCK_POS;
 
-                printk(KERN_INFO "NAND device: Manufacturer ID:"
-                       " 0x%02x, Chip ID: 0x%02x (%s %s)\n", nand_maf_id, nand_dev_id,
-                       nand_manuf_ids[maf_id].name, nand_flash_ids[i].name);
-                break;
+        /* Get chip options, preserve non chip based options */
+        this->options &= ~NAND_CHIPOPTIONS_MSK;
+        this->options |= nand_flash_ids[i].options & NAND_CHIPOPTIONS_MSK;
+
+        /*
+         * Set this as a default. Board drivers can override it, if necessary
+         */
+        this->options |= NAND_NO_AUTOINCR;
+
+        /* Check if this is a not a samsung device. Do not clear the
+         * options for chips which are not having an extended id.
+         */
+        if (*maf_id != NAND_MFR_SAMSUNG && !nand_flash_ids[i].pagesize)
+                this->options &= ~NAND_SAMSUNG_LP_OPTIONS;
+
+        /* Check for AND chips with 4 page planes */
+        if (this->options & NAND_4PAGE_ARRAY)
+                this->erase_cmd = multi_erase_cmd;
+        else
+                this->erase_cmd = single_erase_cmd;
+
+        /* Do not replace user supplied command function ! */
+        if (mtd->oobblock > 512 && this->cmdfunc == nand_command)
+                this->cmdfunc = nand_command_lp;
+
+        printk(KERN_INFO "NAND device: Manufacturer ID:"
+               " 0x%02x, Chip ID: 0x%02x (%s %s)\n", *maf_id, dev_id,
+               nand_manuf_ids[maf_idx].name, type->name);
+
+        return type;
+}
+
+/* module_text_address() isn't exported, and it's mostly a pointless
+   test if this is a module _anyway_ -- they'd have to try _really_ hard
+   to call us from in-kernel code if the core NAND support is modular. */
+#ifdef MODULE
+#define caller_is_module() (1)
+#else
+#define caller_is_module() \
+        module_text_address((unsigned long)__builtin_return_address(0))
+#endif
+
+/**
+ * nand_scan - [NAND Interface] Scan for the NAND device
+ * @mtd:        MTD device structure
+ * @maxchips:   Number of chips to scan for
+ *
+ * This fills out all the uninitialized function pointers
+ * with the defaults.
+ * The flash ID is read and the mtd/chip structures are
+ * filled with the appropriate values. Buffers are allocated if
+ * they are not provided by the board driver
+ * The mtd->owner field must be set to the module of the caller
+ *
+ */
+int nand_scan(struct mtd_info *mtd, int maxchips)
+{
+        int i, busw, nand_maf_id;
+        struct nand_chip *this = mtd->priv;
+        struct nand_flash_dev *type;
+
+        /* Many callers got this wrong, so check for it for a while... */
+        if (!mtd->owner && caller_is_module()) {
+                printk(KERN_CRIT "nand_scan() called with NULL mtd->owner!\n");
+                BUG();
         }
 
-        if (!nand_flash_ids[i].name) {
+        /* Get buswidth to select the correct functions */
+        busw = this->options & NAND_BUSWIDTH_16;
+        /* Set the default functions */
+        nand_set_defaults(this, busw);
+
+        /* Read the flash type */
+        type = nand_get_flash_type(mtd, this, busw, &nand_maf_id);
+
+        if (IS_ERR(type)) {
                 printk(KERN_WARNING "No NAND device found!!!\n");
                 this->select_chip(mtd, -1);
-                return 1;
+                return PTR_ERR(type);
         }
 
+        /* Check for a chip array */
         for (i = 1; i < maxchips; i++) {
                 this->select_chip(mtd, i);
-
                 /* Send the command for reading device ID */
                 this->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
-
                 /* Read manufacturer and device IDs */
                 if (nand_maf_id != this->read_byte(mtd) ||
-                    nand_dev_id != this->read_byte(mtd))
+                    type->id != this->read_byte(mtd))
                         break;
         }
         if (i > 1)
                 printk(KERN_INFO "%d NAND chips detected\n", i);
 
-        /* Allocate buffers, if necessary */
-        if (!this->oob_buf) {
-                size_t len;
-                len = mtd->oobsize << (this->phys_erase_shift - this->page_shift);
-                this->oob_buf = kmalloc(len, GFP_KERNEL);
-                if (!this->oob_buf) {
-                        printk(KERN_ERR "nand_scan(): Cannot allocate oob_buf\n");
-                        return -ENOMEM;
-                }
-                this->options |= NAND_OOBBUF_ALLOC;
-        }
-
-        if (!this->data_buf) {
-                size_t len;
-                len = mtd->oobblock + mtd->oobsize;
-                this->data_buf = kmalloc(len, GFP_KERNEL);
-                if (!this->data_buf) {
-                        printk(KERN_ERR "nand_scan(): Cannot allocate data_buf\n");
-                        nand_free_kmem(this);
-                        return -ENOMEM;
-                }
-                this->options |= NAND_DATABUF_ALLOC;
-        }
-
         /* Store the number of chips and calc total size for mtd */
         this->numchips = i;
         mtd->size = i * this->chipsize;
-        /* Convert chipsize to number of pages per chip -1. */
-        this->pagemask = (this->chipsize >> this->page_shift) - 1;
+
+        /* Allocate buffers and data structures */
+        if (nand_allocate_kmem(mtd, this))
+                return -ENOMEM;
+
         /* Preset the internal oob buffer */
-        memset(this->oob_buf, 0xff, mtd->oobsize << (this->phys_erase_shift - this->page_shift));
+        memset(this->oob_buf, 0xff,
+               mtd->oobsize << (this->phys_erase_shift - this->page_shift));
 
-        /* If no default placement scheme is given, select an
-         * appropriate one */
+        /*
+         * If no default placement scheme is given, select an appropriate one
+         */
         if (!this->autooob) {
-                /* Select the appropriate default oob placement scheme for
-                 * placement agnostic filesystems */
                 switch (mtd->oobsize) {
                 case 8:
                         this->autooob = &nand_oob_8;
@@ -2574,29 +2630,32 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                         this->autooob = &nand_oob_64;
                         break;
                 default:
-                        printk(KERN_WARNING "No oob scheme defined for oobsize %d\n", mtd->oobsize);
+                        printk(KERN_WARNING "No oob scheme defined for "
+                               "oobsize %d\n", mtd->oobsize);
                         BUG();
                 }
         }
 
-        /* The number of bytes available for the filesystem to place fs dependend
-         * oob data */
+        /*
+         * The number of bytes available for the filesystem to place fs
+         * dependend oob data
+         */
         mtd->oobavail = 0;
         for (i = 0; this->autooob->oobfree[i][1]; i++)
                 mtd->oobavail += this->autooob->oobfree[i][1];
 
         /*
-         * check ECC mode, default to software
-         * if 3byte/512byte hardware ECC is selected and we have 256 byte pagesize
-         * fallback to software ECC
+         * check ECC mode, default to software if 3byte/512byte hardware ECC is
+         * selected and we have 256 byte pagesize fallback to software ECC
          */
-        this->eccsize = 256;    /* set default eccsize */
+        this->eccsize = 256;
         this->eccbytes = 3;
 
         switch (this->eccmode) {
         case NAND_ECC_HW12_2048:
                 if (mtd->oobblock < 2048) {
-                        printk(KERN_WARNING "2048 byte HW ECC not possible on %d byte page size, fallback to SW ECC\n",
+                        printk(KERN_WARNING "2048 byte HW ECC not possible on "
+                               "%d byte page size, fallback to SW ECC\n",
                                mtd->oobblock);
                         this->eccmode = NAND_ECC_SOFT;
                         this->calculate_ecc = nand_calculate_ecc;
@@ -2609,7 +2668,8 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
         case NAND_ECC_HW6_512:
         case NAND_ECC_HW8_512:
                 if (mtd->oobblock == 256) {
-                        printk(KERN_WARNING "512 byte HW ECC not possible on 256 Byte pagesize, fallback to SW ECC \n");
+                        printk(KERN_WARNING "512 byte HW ECC not possible on "
+                               "256 Byte pagesize, fallback to SW ECC \n");
                         this->eccmode = NAND_ECC_SOFT;
                         this->calculate_ecc = nand_calculate_ecc;
                         this->correct_data = nand_correct_data;
@@ -2621,7 +2681,8 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                 break;
 
         case NAND_ECC_NONE:
-                printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. This is not recommended !!\n");
+                printk(KERN_WARNING "NAND_ECC_NONE selected by board driver. "
+                       "This is not recommended !!\n");
                 this->eccmode = NAND_ECC_NONE;
                 break;
 
@@ -2631,12 +2692,14 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                 break;
 
         default:
-                printk(KERN_WARNING "Invalid NAND_ECC_MODE %d\n", this->eccmode);
+                printk(KERN_WARNING "Invalid NAND_ECC_MODE %d\n",
+                       this->eccmode);
                 BUG();
         }
 
-        /* Check hardware ecc function availability and adjust number of ecc bytes per
-         * calculation step
+        /*
+         * Check hardware ecc function availability and adjust number of ecc
+         * bytes per calculation step
          */
         switch (this->eccmode) {
         case NAND_ECC_HW12_2048:
@@ -2647,15 +2710,20 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
                 this->eccbytes += 3;
         case NAND_ECC_HW3_512:
         case NAND_ECC_HW3_256:
-                if (this->calculate_ecc && this->correct_data && this->enable_hwecc)
+                if (this->calculate_ecc && this->correct_data &&
+                    this->enable_hwecc)
                         break;
-                printk(KERN_WARNING "No ECC functions supplied, Hardware ECC not possible\n");
+                printk(KERN_WARNING "No ECC functions supplied, "
+                       "Hardware ECC not possible\n");
                 BUG();
         }
 
         mtd->eccsize = this->eccsize;
 
-        /* Set the number of read / write steps for one page to ensure ECC generation */
+        /*
+         * Set the number of read / write steps for one page depending on ECC
+         * mode
+         */
         switch (this->eccmode) {
         case NAND_ECC_HW12_2048:
                 this->eccsteps = mtd->oobblock / 2048;
@@ -2677,15 +2745,6 @@ int nand_scan(struct mtd_info *mtd, int maxchips)
 
         /* Initialize state, waitqueue and spinlock */
         this->state = FL_READY;
-        if (!this->controller) {
-                this->controller = kzalloc(sizeof(struct nand_hw_control),
-                                           GFP_KERNEL);
-                if (!this->controller) {
-                        nand_free_kmem(this);
-                        return -ENOMEM;
-                }
-                this->options |= NAND_CONTROLLER_ALLOC;
-        }
         init_waitqueue_head(&this->controller->wq);
         spin_lock_init(&this->controller->lock);